In advanced cardiac or heart failure the output of the heart may drop from its normal resting output of about 5 liters a minute to an output approaching 2 liters of blood per minute. As output reaches this low level, the kidneys, liver, and brain become irreversibly damaged. In recent years different approaches have been used to treat irreversible cardiac failure. One approach is the removal of the heart and transplantation of a donar organ. While recipients now have a good chance of leading a normal life, obviously the supply of donor organs is limited. Artificial hearts have not been successful as permanent replacements, but have been used on a temporary basis as a "bridge" until a donor heart becomes available. Temporary partial assist devices have been used for acutely failing hearts expected to recover within a matter of days. One such partial assist design is shown in U.S. Pat. No. 4,704,121 which discloses a transarterial insertable blood pump. This device requires a drive cable which extends to the outside of the body of the patient. The pump of this design rotates at an extremely high speed. While this patent does address the problem of blood clotting, the complexities of its design detract from its reliability and additionally the high speed operation has created problems of drive cable reliability. This device also requires an external or internal purge supply, so constant replenishment of the fluid is necessary. In addition to the assist device of the above patent, a mechanical device which entirely replaces heart function has also been proposed, and one such example is shown in the Jarvik patent No. 4,173,796. This type of pump relies upon bladders shifting the blood between two chambers and also requires valves. Typically there is blood stagnation within this form of pump causing the formation of blood clots. This design is also unduly complicated because of its requirement for valves.
All prior art mechanical devices known to date have produced thrombosis and embolization in excess of that normaly produced by the body. In addition, the designs have been complicated and required bulky power supples thereby preventing a normal life.